FLOWERY BRANCH -- It didn't take long for Atlanta Falcons defensive coordinator Mike Nolan to get his players' attention after last week's embarrassing loss at Carolina.

In a meeting with his players this week, Nolan began the session with encouragement, pointing out all that's gone right for a defense that ranks fifth in scoring average.

But Nolan then transitioned to the poor tackling and missed assignments that were a big reason Carolina scored 30 points and piled up 195 yards rushing.

The Falcons were negligent in their tackling technique all afternoon against the Panthers. Plays that should've been stopped in the backfield, at the line of scrimmage or short of a first down turned into huge gains.

Atlanta endured an ugly afternoon as the Panthers ran seven plays that gained between 16 and 22 yards and scored three touchdowns that covered 25, 53 and 75 yards.

"We just made some errors, but we also had several at the beginning -- third-and-2s, third-and-shorts, third-and-5s -- and they broke some tackles on a couple of runs and got 'em, and then we missed the slant play," Nolan said. "They out-executed us."

Nolan's job is to address the deficiencies quickly to ensure they don't become habit-forming, not with the New York Giants (8-5) visiting Atlanta (11-2) on Sunday and the Falcons still trying to earn a top conference seed.

"We don't need to be in a playoff game three or four weeks from now and have those things creep in," Nolan said. "It just shows that they can if you're not on top of your game."

A big area of concern is improving on third down, particularly after Tampa Bay, New Orleans and Carolina combined to average a 50 percent conversion rate over the last three games.

Atlanta's goal is to hold opponents to 33 percent or less.

"Getting stops on third down is almost as good as turnovers because after a special teams play, we're giving the ball back to our offense," free safety Thomas DeCoud said. "Those are things that can swing game momentum from one side to the other. It happened for them in their favor last Sunday."

The Falcons hope to get a boost in the secondary if cornerback Asante Samuel can return this week after missing most of the last two weeks with a right shoulder injury.

It's uncertain if Chris Hope will start for the second straight week at strong safety. William Moore, who intercepted New Orleans star Drew Brees twice in Atlanta, was sidelined against Carolina with a sore hamstring.

Moore missed practice again on Thursday, and Samuel was limited.

DeCoud, however, could sense other factors at play last week, too.

Maybe it's because the Falcons were coming off a big win over the Saints to become the first NFC team to earn a playoff spot, but DeCoud believed the team was emotionally flat.

"Yes, you can be close to perfect, but there are going to times where the ball's not going to bounce in your favor," DeCoud said. "I'd say it was a combination of that and us not really having any energy and kind of going through the motions. If we can get that turned around and make sure we have our passion and energy up and in full swing, be sound in our techniques and assignments, I think things will fall in our favor."

Atlanta's defense struggled on third down all afternoon -- a problem that must be corrected against the Giants. Led by quarterback Eli Manning, New York is third in the NFL in points scored.

But Sean Weatherspoon believes Nolan will help the Falcons fix their flaws before they become a problem.

As Weatherspoon says, there's a reason that Atlanta is fifth in average points.

"We're the same guys that made those plays when we had to," Weatherspoon said.

"We're the same guys that got five picks off of Drew Brees, guys that overcame five interceptions to win a game (against Arizona), guys that got four picks in the first quarter off of Peyton Manning. We've got to get back to the things that made us successful."

Notes: Coach Mike Smith said WR Roddy White won't test his sore right knee until Sunday. White hasn't practiced this week and is not expected to participate today. White, whose 292 catches since the start of 2010 rank second in the league, has never missed a game in his eight-year career.